1. Field of the Invention
The present invention relates to novel polyisoprene compounds, salts thereof, process for the preparation thereof, and use thereof as a pharmaceutical composition to cure a digestive ulcer.
2. Related Arts
Medicines for curing the digestive ulcer have been, in general, classified into two groups of an inhibitor to offensive factors and another group of intensificator to defensive factors. Among them, the former type drugs have been greatly developed, and for instance, a drug of "Cimetidine" which is one of exemplar compounds in the group and one of antagonists to histamine H.sub.2 receptor has provided such a great contribution of that it is excellent high curing ratio to the digestive ulcer, in comparison with other drugs to change a prior surgical treatment which has been mainly employed into an internal treatment administrating the drug.
As a result, various drugs such as "Ranitidine", "Famotidine" and the like have been developed, as antagonists to histamine H.sub.2 receptors, other than said Cimetidine, so that a period of time for curing the digestive ulcer becomes shortened.
However, those drugs are inhibitors to offensive factors and its basis lies in inhibiting secretion of acid in the stomach. This means that if this type drug shows a strong inhibition, it also shows higher acid rebound, and therefor, it becomes such a serious problem that a relapse of the digestive ulcer may happen, when an administration of the drug was cheesed, in accordance with a diagnosis of that the disease has been cured.
In view of the problem on the inhibitor to offensive factors, in recent years, a development of the medicine for curing digestive ulcer has been directed to the latter group type drug, namely the intensificator to defensive factors.
Hitherto, drugs of "Gefarnate", "Cetraxate", "Teprenone" and the like have been developed, as the intensificators to defensive factors and have widely been employed for clinical treatment of the digestive ulcer, since those show a little side-effect and may be administered currently with another drug.
However, all of the latter type drugs do not show high anti-ulcer activity.